Integration examples: update the AMP creative (#7911)

* fixing the AMP creative

There's no way the original version of this ever worked. AMP requires calling out to Prebid Cache. The original example was calling for Prebid.js, which isn't present in an AMP environment. 

I just copied the instructions at https://docs.prebid.org/adops/setting-up-prebid-for-amp-in-dfp.html

* added quotes

integrationExamples/gpt/amp/creative.html

@@ -1,38 +1,16 @@
 <!-- This script tag should be returned by your ad server -->
 
+<script src="https://cdn.jsdelivr.net/npm/prebid-universal-creative@latest/dist/creative.js"></script>
 <script>
-    // This is the `renderAd` function from Prebid.js moved within the creative iframe
-  var renderAd = function (ev) {
-    var key = ev.message ? "message" : "data";
-    var data = {};
-    try {
-      data = JSON.parse(ev[key]);
-    } catch (e) {
-      // Do nothing.  No ad found.
-    }
-    if (data.ad || data.adUrl) {
-      if (data.ad) {
-        document.write(data.ad);
-        document.close();
-      } else if (data.adUrl) {
-        document.write('<IFRAME SRC="' + data.adUrl + '" WIDTH="'+ data.width +'" HEIGHT="'+ data.height +'" FRAMEBORDER="0" SCROLLING="no" MARGINHEIGHT="0" MARGINWIDTH="0" TOPMARGIN="0" LEFTMARGIN="0" ALLOWTRANSPARENCY="true"></IFRAME>');
-        document.close();
-      }
-    }
-  };
+  var ucTagData = {};
+  ucTagData.adServerDomain = "";
+  ucTagData.pubUrl = "%%PATTERN:url%%";
+  ucTagData.targetingMap = "%%PATTERN:TARGETINGMAP%%";
+  ucTagData.hbPb = "%%PATTERN:hb_pb%%";
 
-  var requestAdFromPrebid = function () {
-    var message = JSON.stringify({
-      message: 'Prebid creative requested: %%PATTERN:hb_adid%%',
-      adId: '%%PATTERN:hb_adid%%'
-    });
-    window.parent.postMessage(message, '*');
-  };
-
-  var listenAdFromPrebid = function () {
-    window.addEventListener("message", renderAd, false);
-  };
-
-  listenAdFromPrebid();
-  requestAdFromPrebid();
+  try {
+    ucTag.renderAd(document, ucTagData);
+  } catch (e) {
+    console.log(e);
+  }
 </script>